1. Field of the Invention
This invention relates to apparatus and methods for straightening carpet, and more particularly, to an apparatus for straightening carpet after it has left the mill and is otherwise ready for installation.
2. Brief Description of the Prior Art
Carpet is produced at mills in large rolls as is well known. The length or longitudinal direction of the carpet in these rolls can be several times the width or transverse direction of the roll. As the carpet is produced at the mill, the woven or tufted material is notoriously not straight. That is, the weave can vary considerably along the length of the carpet. This is not a significant problem for plain carpet, but it can be very noticeable on carpet which has a pattern in it, particularly when that pattern has a transversely extending feature to it. For example, a carpet which nominally has a plurality of transversely extending parallel straight lines may actually look like it has wavy lines in it.
Historically, these problems with lack of straightness in carpet patterns have had to be fixed by the carpet installer. That is, when laying the carpet, the installer has had to pull longitudinally on the carpet at various places along its length to bring the pattern back into its proper relationship. Using the parallel line example again, the installer has to pull to stretch the carpet until the transverse lines actually appear straight There are a number of tools designed to engage the surface of the carpet and allow for such stretching. Many of these devices are manually operated, although some have mechanical actuation such as by a hydraulic cylinder. All have disadvantages in that they must be moved to the installation site and relocated on the surface of the carpet at each point in the installation process at which the installer decides is necessary. This greatly increases installation time and cost for laying patterned carpet and can require considerable physical exertion by the installer.
Another problem is that, even with these straightening techniques, mill tolerances are sometimes so great that installers cannot get the carpet straight enough manually and noticeable variations remain.
There is a need, therefore, for an apparatus for straightening carpet at the installation site, or elsewhere, which reduces the time required in prior art installations and is not so physically demanding on installation personnel. The present invention solves this problem by providing an apparatus comprising a heating section wherein the backing on the carpet is softened enough that the carpet can be straightened even when the pattern varies so much that normal manual straightening techniques on carpet at ambient temperatures are not sufficient. As the carpet exits the heating section, it enters a hydraulically controlled straightening section which allows-forces in a longitudinal direction to be applied at various locations across the width of the carpet. This powered stretching allows the operator to straighten the heated carpet regardless of the large tolerances in the pattern. After straightening, the apparatus has a cooling section in which the carpet is allowed to cool after being stretched so that the pattern remains straight. The carpet then exits the apparatus with the pattern straightened. The roll of carpet may then be installed much more quickly because the installer does not have to do as much to the carpet as it is laid on the floor.
The present invention includes an apparatus for straightening carpet so that the carpet is more easily laid down. The apparatus can be used at any location including where the carpet is to be installed.
The invention may be described as an apparatus for straightening carpet comprising a heating section for heating at least a portion of a roll of carpet such that a backing material on the carpet is softened, and a straightening section which is adapted for applying stretching forces to the heated carpet, whereby the carpet is straightened while the backing is softened and remains substantially straight after the backing is cooled.
The apparatus may further comprise an entry section adjacent to the heating section and adapted for receiving the roll of carpet thereon. The entry section preferably comprises an entry conveyor having an upwardly concave curvilinear configuration adjacent to an entry side of said heating section. The entry conveyor may define a recess adapted for receiving the roll of carpet. In one embodiment, the entry conveyor comprises a curvilinear support and a plurality of rollers disposed on the support
The heating section comprises a duct, having an entry side and an exit side, and a heater disposed in the duct between the entry and exit sides. The heating section preferably further comprises a blower in communication with the duct for blowing air therethrough and across the heater.
In one embodiment, the duct comprises a lower duct and an upper duct in communication with said duct. The blower is in communication with the lower duct. The lower duct may be divided into a pair of sections, each having a blower in communication therewith. In this embodiment, the heater is preferably disposed within said lower duct. The heater may be characterized as one of a plurality of finned strip heaters.
The straightening section comprises a straightening table on which the carpet may be moved after exiting the heating section and a straightening array for engaging said carpet and applying said forces thereto. The straightening array comprises a plurality of straightening plates adapted for gripping engagement with the carpet and a corresponding plurality of cylinders pivotally connected to the straightening plates for actuating the straightening plates into and out of engagement with the carpet.
The straightening section has a duct with a blower in communication therewith for blowing air along an underside of the straightening table. Heaters are used to heat the air such that heat is transferred to the straightening table to keep heat applied to the carpet during the straightening operation.
The straightening section further comprises a clamping array for engaging and holding the carpet as the straightening array applies the stretching forces to the carpet. The clamping array comprises a plurality of clamping plates adapted for gripping engagement with the carpet and a corresponding plurality of cylinders connected to the clamping plates for actuating the clamping plates into and out of engagement with the carpet. In one embodiment, the clamping array is one of a plurality of clamping arrays.
The carpet straightening apparatus further comprises a cooling section on an opposite side of the straightening section from the heating section. The cooling section comprises a table on which the carpet lays substantially flat.
The straightening and clamping arrays are mounted on tracks so that they are movable along and between the straightening and cooling tables. The straightening and clamping arrays may be locked together with a locking bar so that the arrays are simultaneously movable.
The apparatus also comprises an exit section for receiving the carpet after it exits the straightening and cooling sections. The exit section preferably comprises an exit conveyor with an upwardly concave curvilinear configuration adjacent to the cooling section. The exit conveyor preferably defines a recess adapted for receiving the roll of carpet as it is moved away from said cooling section. In one embodiment, the exit conveyor comprises a curvilinear support and a plurality of rollers thereon disposed on said support.
Numerous objects and advantages of the invention will become apparent as the following detailed description of the preferred embodiment is read in conjunction with the drawings illustrating such embodiment.